>> fbi agents comb the debris for clues to who could have been behind the bombing. they quickly locate a very revealing piece of evidence. >> it was within three hours of the bombing itself that the rear axle to the bomb-laden truck was located and found. that rear axle had a confidential vehicle identification number which led to the ryder truck and took us to kansas to start the investigation there to who rented that vehicle. >> federal agents swarmed junction city, kansas, and talked to the owner of elliott's body shop, where the rental truck was emerged. they come away with a description of robert kling. down the street, the manager tells agents that the description resembles a man who had just stayed there, a guest registered under the name tim mcveigh. the question remains, why would he use his real name? it's turning out mcveigh has left clues everywhere. >> you have to realize that inside that marquee was a big thick brown envelope with all kinds of antigovernment literature, espousing his viewpoints. and he's wearing a t-shirt that has a quote from john wil